Enjoying these. Thanks for showing. Two strokes give me sinus so I usually avoid pedestrian ones. High performance ones I can't resist. Had many of various types over the years.
Ah , thank goodness, I have the same guide that you have and followed it as you did but it doesn't change gear on the bench . I rebuilt one previously which also wouldn't change gear but that one was caused by a selector roller falling off . My current theory is the mainsheet bearing that sits behind the drive sprocket is worn and not keeping the shaft centrally. I stripped it to fit a new crankshaft.
After I fix the front brake, my next job is to finish off this engine and put it back in the bike I am keeping my fingers crossed that the gearbox will work it has a lot of used parts from eBay.
Hey Brad, the gearbox bushes really need to be line reamed to ensure they are correctly aligned. You might get away with reaming them individually but it won't be as good as it should be. BSA made a tool for doing this job but they are like hen's teeth these days. I think you will struggle with an adjustable reamer like you mentioned to me in another comment. The collar at the end will prevent you from reaming right to the end. I think you'll need to mic up the shaft and get a parallel reamer to suit, them perhaps make a guide that bolts to the outside of the opposite case and line ream. Send me an email and we can discuss it further. Best wishes, Dean. Ps, I've subscribed to your channel.
Hi Dean, I looked on your channel and couldn't find any way to contact you directly. I have just purchased Vernier calipers and the layshaft diameter is 0.608 inches so if I use a 5/8 (0.625 inch) reamer I should have a 0.017 inch larger hole not sure if this is going to be to lose the other option is to use a 15.5 mm (0.610 inches) reamer I think I will go for the latter option. I have a pedestal drill so if I put both crankcases together and turn it by hand I hope it will be accurate enough as I very much doubt I will find the service tool. I will also post on Bantam forum/Facebook group thanks your input if you think this is the wrong way to do please let me know. Thanks, Brad
@@bradwalton7599 my channel email address is usually at the beginning or end of a video, it's at the end of the latest one about the milling machine and in the description. 5/8 sounds right from memory for the layshaft but definitely worth going to the smaller size first. Your method of reaming in the pedestal drill sounds viable, as long as you have the job well secured and at true 90 degrees to the reamer. If the drill will run dead slow you will get a nice finish under power. Flood the job with lots of lubricant and it should work out well. Best wishes, Dean.
Thanks for the reply. After watching your video I remembered I had a set of taps. I used a 16mm to grab the Bush and applied heat to the casing. It came out without a fight. Cheers.
very helpful video , i was able to follow you through step by step .
Enjoying these. Thanks for showing. Two strokes give me sinus so I usually avoid pedestrian ones. High performance ones I can't resist. Had many of various types over the years.
I did have a modified Yamaha RZ250 in the 90s worthless then no body wanted them. I wished I kept it.
Ah , thank goodness, I have the same guide that you have and followed it as you did but it doesn't change gear on the bench . I rebuilt one previously which also wouldn't change gear but that one was caused by a selector roller falling off . My current theory is the mainsheet bearing that sits behind the drive sprocket is worn and not keeping the shaft centrally. I stripped it to fit a new crankshaft.
After I fix the front brake, my next job is to finish off this engine and put it back in the bike I am keeping my fingers crossed that the gearbox will work it has a lot of used parts from eBay.
Hey Brad, the gearbox bushes really need to be line reamed to ensure they are correctly aligned. You might get away with reaming them individually but it won't be as good as it should be. BSA made a tool for doing this job but they are like hen's teeth these days.
I think you will struggle with an adjustable reamer like you mentioned to me in another comment. The collar at the end will prevent you from reaming right to the end. I think you'll need to mic up the shaft and get a parallel reamer to suit, them perhaps make a guide that bolts to the outside of the opposite case and line ream. Send me an email and we can discuss it further. Best wishes, Dean.
Ps, I've subscribed to your channel.
Hi Dean, I looked on your channel and couldn't find any way to contact you directly. I have just purchased Vernier calipers and the layshaft diameter is 0.608 inches so if I use a 5/8 (0.625 inch) reamer I should have a 0.017 inch larger hole not sure if this is going to be to lose the other option is to use a 15.5 mm (0.610 inches) reamer I think I will go for the latter option. I have a pedestal drill so if I put both crankcases together and turn it by hand I hope it will be accurate enough as I very much doubt I will find the service tool. I will also post on Bantam forum/Facebook group thanks your input if you think this is the wrong way to do please let me know. Thanks, Brad
@@bradwalton7599 my channel email address is usually at the beginning or end of a video, it's at the end of the latest one about the milling machine and in the description.
5/8 sounds right from memory for the layshaft but definitely worth going to the smaller size first. Your method of reaming in the pedestal drill sounds viable, as long as you have the job well secured and at true 90 degrees to the reamer. If the drill will run dead slow you will get a nice finish under power. Flood the job with lots of lubricant and it should work out well. Best wishes, Dean.
Great video. I need to replace the blind bush in my D14 but don't know how to remove the old one. How did you remove yours.
I applied mild heat to the case and then tapped it out from behind.
Thanks for the reply. After watching your video I remembered I had a set of taps. I used a 16mm to grab the Bush and applied heat to the casing. It came out without a fight. Cheers.
Where you get the pics for the gear box from
Hi, In the description I placed two links to the guides I used.